Can a subdomain have a different reputation than the root domain?

Yes, subdomains can and do have reputations that differ significantly from their root domain. Each subdomain is evaluated based on its own authentication records, sending patterns, engagement metrics, and complaint rates.

A subdomain used exclusively for high-quality transactional mail might have excellent reputation while the root domain used for aggressive marketing struggles. The reverse can also occur.

Providers do track the relationship between subdomains and root domains. Severe abuse on a subdomain can eventually affect trust in the parent, especially if the pattern suggests organizational neglect rather than an isolated issue.

Think of subdomains as branch offices of your shipping company. Each maintains its own local reputation with port authorities, but the headquarters' name still appears on the letterhead, and chronic problems at branches will eventually tarnish the whole operation.